Multi-feed knitting machine for reinforcing flexible hose or the like



.1. GRECZIN 3,257,828 MULTI-FEED KNITTING MACHINE FOR REINFORCING June28, 1966 FLEXIBLE HOSE OR THE LIKE 2 Sheets-Sheet 1 Filed 001,. l, 1965ATTYS.

June 28, 1966 J. GRECZIN 3,257,328

MULTI-FEED KNITTING MACHINE FOR REINFORCING FLEXIBLE HOSE OR THE LIKE 2Sheets-Sheet 2 Filed Oct. 1, 1965 FIG-4.

INVENTOR. JOHN GRECZIN Mai 69 ATTYS.

' one relative revolution of the cylinder.

United States Patent "ice 3,257,828 MULTI-FEED KNITTING MACHINE FORREIN- FORCING FLEXIBLE HOSE OR THE LIKE John Greczin, Philadelphia, Pa.,assignor to The Singer Company, New York, N.Y., a corporation of NewJersey Filed Oct. 1, 1963, Ser. No. 312,971 2 Claims. (Cl. 66-38) Thepresent invention relates to circular knitting machines and particularlyto circular knitting machines of the type which make a knit tubularfabric for reinforcing flexible hose and the like.- I

In circular knitting machines knitted fabric is formed by yarnscooperating with reciprocating needles mounted about the periphery of aneedle cylinder, and the reciprocation of the needles is caused byrelative movement or rotation between a cam box and the needles. In thepresent state of the art of small-cylinder circular knitting machines,it is diflicult and highly impractical to attempt to obtain more'thanfour courses for every relative revolution between the cam box and theneedles. The number of courses that may be produced in a smallcylindercircular knitting machine during one relative revolution, is limited bythe means by which the needles are caused to reciprocate to formstitches. The most common means for causing the needles to reciprocatein machines of this variety is a cam track in the cam box in which ridesa projection from the needle, commonly called the needle butt, whichfirst raises the needle by engagement of the lower portion of the buttin the cam track and then lowers the needle to draw the stitch byengagement of the upper portion of the needle butt in the cam track.Thus the number of courses of knitted fabric which each needle may knitduring one revolution of the cylinder with respect to the cams isdetermined by the number of times that the needle raises or lowersduring any one relative revolution of the cylinder, there being aseparate yarn feed adjacent each point where the needle reaches itsuppermost position.

It has been found that if the angle which the normal to a cam vtrackmakes with the longitudinal axis of a needle exceeds 45 degrees (45),binding of the needle butts, excessive wear, and in many instancesSmashups occur. Thus the limitation is imposed that the smaller thediameter of the knitting machines needle cylinder, the fewer the yarnfeeds that may be used, and consequently the fewer the number of courseswhich may be knit in From the foregoing then it is readilyunderstandable that in comparatively large diameter circular knittingmachines, the number of feeds, and consequently the number of coursesper revolution of the cylinder, may be increased in accordance with thisincreased circumferential size, because the cam track which the butt ofthe needle must follow may easily increase the number of reciprocationsof the needle without exceeding the 45-degree angle limitation. However,it should be noted that the larger the diameter of the cylinder of themachine the larger the diameter of the material being knit, and in thecase of knitting, for example, a reinforcing web for small diameterflexible hose, the use of a large diameter machine is undesirable andimpracticable.

In accordance with the present invention, means are provided wherein aplurality of courses may be knit upon one revolution of the cylinder.More specifically, the present invention provides means forcircumventing the 45-degree angle limitation thereby permitting anincreased number of knitted courses per revolution.

Another object of the present invention is to produce a small diametertubular fabric much more rapidly than heretofore known in the art onsmall cylinder knitting machines.

3,257,828 Patented June 28, 1966 Another object of the present inventionis to produce a tubular knitted fabric composed of individual mutuallyoverlying knitted webs to provide a smooth front and back face in thefabric and to improve the burst strength of flexible hose or the like.

Other objects and a fuller understanding of the invention may be had byreferring to the following description and claims taken in conjunctionwith the accompanying drawings in which:

FIG. 1 is a vertical sectional view through a portion of a knittingmachine constructed in accordance with the present invention withportions of the machine broken away to more clearly illustrate itsconstruction;

FIG. 2 is a perspective view of the upper portion of ,the knittingmachine illustrated in FIG. 1;

FIG. 3 is a transverse sectional view taken on line 33 of FIG. 1;

FIG. 4 is a diagrammatic representation illustrating the operation ofthe machine of the present invention, showing at the upper portion ofthe figure the movement of the needles and feeds as seen from the insideof the needle circle, showing in the mid portion of the figure thefabric formed thereby inverted, and as seen from the inside of theupwardly moving web, and show-ing at the lower portion of the figure,the cam tracks controlling the movement of the needles at a reducedscale to enable diagrammatic correlation with the needles shown in theupper portion of the figure; and

FIGS. 5, 6, 7, and 8 show a portion of the needles shown in the upperportion of FIG. 4, as the yarn feed progresses through degrees relativeto the needles.

.Referring now to the drawings, and particularly to FIGS. 1 through 3, ahose 10 has a reinforcing fabric 12 knitted about the outer periphery ofthe hose. The fabric 12 is composed of two tubular webs knitted fromseparate yarns and on separate sets of needles. The

needles are so arranged in the cylinder that those of one set alternatewith those of the other set. Consequently the wales 20 of one webalternate with the wales 30 of the other web about the circumference ofthe composite fabric.

In the present embodiment of the invention, each web of the compositefabric 12 is formed by four feeds so that in each wale, every fourthneedle loop is formed by the same yarn feed. The Web having the wales20. is formed of four yarns, 21, 22, 23, and 24 which are drawn intoneedle loops 21a through 24a respectively. The connecting runs 2112through 24b which are associated with yarns 21 through 24 respectively,lie behind the loops forming the wales 30 of the'other web as more fullyset forth hereinafter. The web having the wales 30 is formed in a likemanner to the web having the wales 20, comprising four yarns 31, 32, 33,and 34 with respective needle loops 31a through 34a and associatedconnecting runs 31b through 34b.

In the present instance, the webs are knit with the needle loopsdisposed on the rear face of the fabric and the connecting runs on thefront face of the fabric. This means that the smooth side of the fabric,that is the jersey knit side, is adjacent the outer periphery of thehose 10. As shown in the drawings, the connecting runs of each adjoiningset of wales of each web in any one course pass in front of the needleloops of the intervening wale of the other web.

Referring now to the apparatus shown in FIG. 1, the knitting machinecomprises a stationary hollow needle cylinder 101 having a reduced uppersection 102 and an enlarged lower section 103. The needles are placed ininteriorly grooved vertical needle bars which are retained in the lowersection 103 of the. needle cylinder 101 by a clamp 117. Similar needlegrooves are provided in the exterior of the upper section 102 inaccordance with the conventional practice. Referring to FIGS. 1, 2, and3, two sets of needles 120 and 130, in the present instance, eightneedles in each set, are retained in the needle grooves by suitableretaining means 104 and define a needle circle. The needles 120 and 130are conventional in form, and include the usual hook 140 and latch 150.The needles 120 and 130 are mounted for vertical reciprocation in theneedle grooves and to this end, are provided with butts 105 and 106respectively which radially project from the needle shank, and engage incam tracks 107 and 108 formed in a cam box, in the present instance arotary barrel cam 109 which is slidable on the stationary central post110 of the needle cylinder. Means (not shown) is provided to cooperatewith the lower portion 111 of the barrel cam 109 to rotate the same andeffect longitudinal reciprocation of the needles in the stationarycylinder. A rotary knitting head 113 is axially aligned with the needlecylinder 101 and is provided to cooperate with the verticallyreciprocating needles 120 and 130 to form a knitted web. The head 113 isrotated synchronously with the barrel cam 109 by conventional drivemechanism (not shown) and includes a depending tubular member 114 whichembraces the upper portion of the needle sets 120 and 130 when theneedles are in the stitch clearing position. As is illustrated in FIG.3, two sets of yarn are fed through body yarn feed apertures in thetubular member 114. The first set of yarn feeds comprises the feedapertures 121- 124 to feed the body yarns 21, 22, 23, and 24respectively and the second set of yarn feeds comprises the feedapertures 131134 to feed the body yarns 31 through 34 respectively. Asis illustrated in FIG. 1, the knitting head 113 terminates in spacedrelation to the needle cylinder 101 to define an annular work slot 116through which the knitted web may be drawn.

As previously explained if the angle (hereinafter referred to as thepressure angle) which the normal to a cam track makes with thelongitudinal axis of a needle exceeds 45 degrees, binding of the needlebutts, excessive wear and in many instances smashups occur. Thusheretofore, the number of courses which may be knit during onerevolution of the cylinder with respect to the cams Was limited by thenumber of times that a needle raises or lowers during any one relativerevolution of the cylinder, which, as has beenexplained is, in turn,limited by the pressure angle of the cam track.

In order to circumvent this problem, and in accordance with one featureof the invention, a plurality of continuous cam tracks are provided, inthe present instance two, axially spaced from each other along the cambox and so arranged as to permit the maximum number of reciprocationsduring one revolution of the knitting cylinder with respect to the camswithout exceeding the pressure angle limitation. As may be notedin FIG.4, each of the cam tracks, 107 and 108, provides four completereciprocations of the needles of the sets 120 and 130 respectivelyduring one revolution of the cam box. It should be noted that if the camtracks were designed to provide an additional reciprocation of theirrespective needle sets in one revolution, with the same diameter cam boxand the same vertical distance moved in one reciprocation of theneedles, the cam tracks would of necessity exceed the pressure anglelimitation. Thus the cam track 107 permits the maximum number ofreciprocations of the needle set 120, in one relative revolution withrespect to said needles, without exceeding the pressure angle limitationof 45 degrees. In a like manner, the cam track 108 associated with theneedle set 130 is designed for the maximum number of reciprocations ofthe needle set 130 without exceeding the pressure angle limitation of 45degrees. In the present instance, as there are four feeds associatedwith each set of needles, eight courses of knitted fabric are formed forevery revolution of the cam box 109. As is illus- 4 trated in FIG. 1,the cam tracks 107 and 108 are in out-of-phase alignment such that whena needle, for example in cam track 107, is at the knocking over point,the adjacent needle in cam track 108 is approaching the clearing level.Although the cam tracks have been illustrated in this relation, itshould be understood that they may be offset from one another so as toprovide a different relationship with respect to the needles. This ofcourse could cause the formation of an entirely different fabric. Thus aplurality of cam tracks, each associated with a separate set of needlesand yarn feeds, and each cam track of at least two of the plurality oftracks providing a maximum number of reciprocations of its associatedneedle set without exceeding the pressure angle limitation, provides themaximum number of courses that may be knit in one relative revolution ofthe needle cylinder.

In accordance with another feature of the invention, in order to providea double web in lieu of a double knit, and in order to prevent theneedles of any one set 130 from catching the yarn being fed from theyarn feed associated with the other set of needles, radial clearance isprovided between the rearward edge of the hook of the needles and andthe tubular portion 114 of the rotary knitting head 113. To this end thetubular member 114 has an outer portion 114a through which the yarn isfed, and a coaxial inner portion 114b. The inner portion 11412 has aninternal diameter suflicient to allow passage of the reinforced hosetherethrough and an external diameter sutficient to permit the hooks ofthe needles to pass in front of the inner portion 11411:. As isillustrated in FIGS. 1 and 2, the outer periphery of the inner portion11412 is shaved, thereby defining a passage between the hooks and theinner portion where yarns not associated with the particular needle maypass. It should be noted however that the same result could be achievedby merely spacing the needles radially from the inner portion 1141) soas to provide the necessary yarn clearance between the rearward edge ofthe hook 140 and the inner portion 114b.

As previously explained the wales 20 of one web alternate with the wales30 of the other web about the circumference of the composite fabric,each web of the composite fabric 12 being formed by four feeds so thatin each wale every fourth needle loop is formed by the same yarn feed.With reference to FIG. 4, the needles of the set 120 are designated1201, through .1208 for the purposes of identification, each of theneedles acting similarly as it is traversed by the rotary knitting head113. The needles 130 are similarly designated 130-1 through 130-8. Itshould be noted that the cam tracks shown diagrammatically at 107 and108 are true developments of the cam tracks on the barrel cam, but areat a reduced scale relative to the needles by reason of the enlargedcircumference of the cam with respect to the reduced circumference ofthe needle circle in the upper section 102 of the cylinder. In orderthat the needle set 120 forms loops only with the yarns 21 through 24,the elevated portion of the cam track 107 corresponding to the stitchclearing height with respect to the needles, is located in generalregistry with the yarn feeds 121 through 124.

In a like manner the highest portions of the cam track 108 whichcorrespond to the stitch clearing position of the needle of the set 130,are also in general registry with the yarns 31 through 34 and thereforethe yarn feeds 131 through 134. Inthis matter each needle associatedwith a particular cam track is displaced downwardly to draw a stitchconcurrently with the passage of the yarn feed associated with thatneedle. As a result of this spacing the cam track 107 is exactly degreesout-of-phase with the cam track 108, so that the stitch clearingposition of the cam track 107 for example corresponds to the loopforming level or knocking over point of the cam track 108 and viceversa.

FIGS. 5 through 8 illustrate the manner in which fabric is knit on themachine. Each of the figures show four of the needles illustrated in theupper portion of FIG. 4, as the feed and the cams progress through 90degrees of rotation with respect to the needles. Referring firs-t toFIG. 5, the needle 130-2 is shown moving in a downward direction so asto draw a loop through the preceding wale loop of yarn 33, held on theshank of the needle 130-2. As shown in FIG. 6, wherein the yarn andearns have moved 22% degrees with respect to the needles, the latch ofthe needle 130-2 has been closed by the Wale loop of yarn 33 and theyarn 33 has been cast from the needle 130-2 with the yarn 32 now engagedin the hook 140 of the needle 130-2. As illustrated in FIG. 7 as theneedle 130-2 commences to move towards its maximum height, the yarn 22is cammed behind the hook 140 of the needle 130-2, because, inaccordance with the invention, the needle 130-2 has been radially spacedfrom the portion 114]) of the knitting head 113, the yarn 22 therebypassing behind the needles hook. As may be seen in FIG. 8 the needle130-2 now engages with the yarn 31 so as-to draw another loop throughthe loop of the yarn 32. Thus in one complete rotation of the cam andthe knitting head, the needle 130-2 forms Wale loops with all of theyarns associated with the yarns 31 through 34. In a like manner theneedles of the set 120 operate upon rotation of the knitting head andthe cams so as to form the wales 20 with associated connecting runswhich lie behind the needle loops of the wales 30. Thus, the two webswhich make up the composite fabric are knitted concurrently on two setsof needles, the needles of one set alternating with the needles of theother set.

Thus, in accordance with the present invention, means are providedwherein a plurality of courses may be knit upon one revolution of thecylinder on a small cylinder circular knitting machine. This isaccomplished in accordance with the present invention by providing anadditional cam track to circumvent the pressure angle limitation therebypermitting an increased number of knitted courses per relativerevolution of the cylinder. Further, in accordance with the presentinvention, means are provided so as to produce a tubular knitted fabriccomposed of individual mutually overlying knitted webs to provide asmooth front and back face in the fabric and to improve the burststrength of flexible hose or the like much more rapidly than heretoforeknown in the art of small cylinder knitting machines.

Although the invention has been described with a certain degree ofparticularity, it is understood that the present disclosure has beenmade only by way of example and that numerous changes in the details ofconstruction and the combination and arrangement of parts may be madewithout departing from the spirit and the scope of the invention ashereinafter claimed.

What is claimed is:

1. A circular knitting machine comprising a hollow needle cylinder andat least two sets of knitting needles slidably mounted thereon, each ofsaid needles having radially projecting butts, a cam box relativelyrotatable with respect to said cylinder and having at least two camtracks the first of which is engagable with the butts of one of saidsets of needles and the second of which is engagable with the butts ofsaid other set of needles so as to provide reciprocation of said needlesupon relative movement between said cam box and said cylinder, said twocam tracks providing a maximum number of reciprocations of itsassociated needle-set between stitch-clearing and stitch-drawing levelsWithout exceeding the pressure angle limitation of 45 degrees, at leasttwo sets of yarn feeds, each of said sets of yarn feeds having thenumber of yarn feeds equal to the number of reciprocations of one ofsaid needles in one of said sets during one relative revolution of saidcam box, each of said sets of yarn feeds adapted to feed yarn to atleast its associated set of needles upon relative movement between saidyarn feeds and said, needles.

2. A circular knitting machine comprising a hollow needle cylinder andat least two sets of knitting needles slidably mounted thereon, each ofsaid needles having radially projecting butts, a cam box relativelyrotatable with respect to said cylinder and having at least two camtracks the first of which is engagable with the butts of one of saidsets of needles and the second of which is engagable with the butts ofsaid other set of needles so as to provide reciprocation of said needlesupon relative movement between said cam box and said cylinder, at leasttwo of said cam tracks providing a maximum number of continuousreciprocations of the needles in its associated set betweenstitch-clearing and stitch-drawing levels without exceeding the pressureangle limitation of 45 degrees, at least two sets of yarn feeds, atleast one of said sets of yarn feeds having at least four yarnscircumferentially positioned about said cylinder, the number of yarns tobe knit equal in number to the number of reciprocations of one of saidneedles in its associated set during one relative revolution of said cambox, each of said sets of yarn feeds adapted to feed said yarn to one ofsaid sets of needles upon relative movement between said yarn feeds andsaid needles.

References Cited by the Examiner DONALD W. PARKER, Primary Examiner.

R. FELDBAUM, Assistant Examiner.

1. A CIRCULAR KNITTING MACHINE COMPRISING A HOLLOW NEEDLE CYLINDER ANDAT LEAST TWO SETS OF KNITTING NEEDLES SLIDABLY MOUNTED THEREON, EACH OFSAID NEEDLES HAVING RADIALLY PROJECTING BUTTS, A CAM BOX RELATIVELYROTATABLE WITH RESPECT TO SAID CYLINDER AND HAVING AT LEAST TWO CAMTRACKS THE FIRST OF WHICH IS ENGAGABLE WITH THE BUTTS OF ONE OF SAIDSETS OF NEEDLES AND THE SECOND OF WHICH IS ENGAGABLE WITH THE BUTTS OFSAID OTHER SET OF NEEDLES SO AS TO PROVIDE RECIPROCATION OF SAID NEEDLESUPON RELATIVE MOVEMENT BETWEEN SAID CAM BOX AND SAID CYLINDER, SAID TWOCAM TRACKS PROVIDING A MAXIMUM NUMBER OF RECIPROCATIONS OF ITSASSOCIATED NEEDLE SET BETWEEN STITCH-CLEARING AND STITCH-DRAWING LEVELSWITHOUT EXCEEDING THE PRESSURE ANGLE LIMITATION OF 45 DEGREES, AT LEASTTWO SETS OF YARN FEEDS, EACH OF SAID SETS OF YARN FEEDS HAVING THENUMBER OF YARN FEEDS EQUAL TO THE NUMBER OF RECIPROCATIONS OF ONE OFSAID NEEDLES IN ONE OF SAID SETS DURING ONE RELATIVE REVOLUTION OF SAIDCAM BOX, EACH OF SAID SETS OF YARN FEEDS ADAPTED TO FEED YARN TO ATLEAST ITS ASSOCIATED SET OF NEEDLES UPON RELATIVE MOVEMENT BETWEEN SAIDYARN FEEDS AND SAID NEEDLES.